Submitted to: Applied and Environmental Microbiology
Publication Type: Peer reviewed journal
Publication Acceptance Date: 3/23/2006
Publication Date: 6/1/2006
Citation: Liu, S., Bayles, D.O., Mason, T.M., Wilkinson, B.J. 2006. A cold-sensitive Listeria monocytogenes mutant has a transposon insertion in a gene encoding a putative membrane protein and shows altered (p)ppGpp levels. Applied and Environmental Microbiology. 72(6):3955-3959. Interpretive Summary: The food-borne pathogen Listeria monocytogenes can cause listeriosis in pregnant woman, infants, elderly, and immuno-compromised individuals. Contaminated Listeria can grow and multiply at refrigeration temperatures during food storage periods. This often leads to product recalls or outbreaks. Fundamental knowledge is needed to understand how L. monocytogenes grows at refrigeration temperatures. We isolated a mutant strain of Listeria that cannot grow at lower temperatures and characterized the gene responsible for this defect. Results will be valuable to researchers developing methods to control the bacterium and reduce future outbreaks.
Technical Abstract: A Listeria monocytogenes cold-sensitive mutant, generated by Tn917 mutagenesis, is mutated in a gene (LMOf2365_1485 homolog) encoding a putative metal-dependent phosphohydrolase. The mutant accumulated higher levels of (p)ppGpp than the wild type, indicating that the function of this phosphohydrolase may be to reduce (p)ppGpp levels during low temperature adaptation.